Flinders bar

A Flinders bar is a vertical soft iron bar placed in a tube on the fore side of a compass binnacle. The Flinders bar is used to counteract the vertical magnetism inherent within a ship and is usually calibrated as part of the process known as swinging the compass, where deviations caused by this inherent magnetism are negated by the use of horizontal (or quadrantal) correctors.

Flinders bar

A Flinders bar is a vertical soft iron bar placed in a tube on the fore side of a compass binnacle. The Flinders bar is used to counteract the vertical magnetism inherent within a ship and is usually calibrated as part of the process known as swinging the compass, where deviations caused by this inherent magnetism are negated by the use of horizontal (or quadrantal) correctors.